Arizona’s season looks very different now with David Johnson out for an extended period.

In 2015, the Arizona Cardinals were one of the hottest teams in the league. After finishing 10-6 and 11-5 the previous two seasons, they solidified their status as one of the top teams in the league, finishing 13-3 while making it to the conference championship.

Running back David Johnson debuted as a rookie in 2015 as well. The Cardinals already had Chris Johnson and Andre Ellington, who were both proven veterans at the time, so the third-round pick was viewed as an afterthought.

As the season went on, Johnson was given more carries and was shining. Finally, after two back-to-back games with over 100 total yards, Johnson had the game of a lifetime. He ran for 187 yards and three touchdowns just four days after his 24th birthday. Johnson was unstoppable that game and even had one of the most impressive runs of the season.

It was at that moment when the Cardinals realized they had found their running back of the future.

Unfortunately, the Cardinals were not as successful in 2016. They finished 7-8-1, failing to reach the postseason despite minimal roster and coaching changes.

The one bright spot for them was Johnson. In his second year, he led the league in yards from scrimmage (2,118) and touchdowns (20) en route to a First-Team All-Pro selection. Coming into this season, Johnson was the consensus top pick in fantasy football drafts and was expected to lead the Cardinals back to the postseason.

All that changed in Week 1, when Johnson dislocated his wrist in the third quarter. The injury means Johnson is likely to miss two-to-three months, the majority of the NFL season.

Johnson’s injury spells immediate trouble for the Cardinals playoff hopes. After the injury, the Cardinals went from a projected wild-card team to a six- or seven-win team, a huge difference for just one player to make.

In the meantime, the Cardinals will need to find a viable solution at running back. They re-signed Chris Johnson after cutting him at the end of the preseason. Once a 2,000-yard rusher, Johnson turns 32 next week and hadn’t started a game since 2015 before yesterday, as he managed just 44 yards. Kerwynn Williams has never started a game at running back and only ran 22 yards on nine carries yesterday for a measly 2.3 yards per carry.

Andre Ellington looks to be the best option at this point, but even he is far from David Johnson’s level. In his only season as the Cardinals’ starting running back in 2014, Ellington averaged an abysmal 3.3 yards per carry, tied for the worst average for a player with over 200 carries.

Instead, the Cardinals will need brilliant play from quarterback Carson Palmer. After an MVP-caliber 2015 season in which he led the league in total QBR (78.6) and game-winning drives (five) while ranking in the top five in yards (fourth), touchdowns (second), and passer rating (third), Palmer struggled in 2016, dropping to 18th in total QBR (58.9) and 20th in passer rating (87.2), while throwing for fewer touchdowns (35 to 26) and more picks (11 to 14).

As Palmer nears age 38, a rebound to 2015 form looks less imminent. For all starting quarterbacks at least 37 years old, only four have had a season as good as Palmer’s 2015 in terms of passer rating.

Unfortunately for him, those four are either in the Hall of Fame (Brett Favre and Y.A. Tittle) or future locks (Peyton Manning and Tom Brady). Palmer, on the other hand, is nowhere near a lock for the Hall of Fame. The best season of a comparable player to Palmer would be Rich Gannon’s 2002 season, in which he passed for 4,689 yards, 26 touchdowns, and 10 interceptions while earning a 97.3 passer rating. So in order to repeat his 2015 season and lead the Cardinals to a playoff run, Palmer would need to play like a Hall of Famer.

The Cardinals’ 2016 woes aren’t all Palmer’s fault. Some of the blame falls on the receivers. Larry Fitzgerald remained a constant force, but both John Brown and Michael Floyd dropped off. After combining for nearly 2,000 yards in 2015, the duo teamed up for fewer than 1,000 in 2016, with the team cutting Floyd after a DUI arrest. With Fitzgerald likely in his final season at age 34, Brown will need to emerge as a reliable target after a down year in which his catch percentage dropped 11 points (64.4 to 53.4).

On the defensive side of the ball, the Cardinals need to be elite. Last season, the team ranked second in yards allowed but ranked just 14th in points allowed. If the Cardinals expect to make the postseason, they need to limit the amount of points they give up.

In order to wreak havoc on defense, the Cardinals need defensive back Tyrann Mathieu to stay healthy. While Mathieu has never started more than 14 games in his four-season career, he has been productive while healthy, earning a First-Team All-Pro selection in 2015.

In addition to Mathieu, the team needs cornerback Patrick Peterson to play some of the best football of his career. The six-time Pro Bowler is already one of the premier shutdown corners in the league, and at age 27, is playing in the prime of his career. If Peterson and Mathieu stay healthy and perform their best, they can lead a top defense in the league.

The Arizona Cardinals are not the same team they were in 2015, and losing David Johnson to injury hurt them. There’s still a chance of making the playoffs, maybe for the last time in Palmer’s and Fitzgerald’s careers, but the veteran leaders on the team will need to play some of the best football of their career.